Replaceable insert



1 Aug. 19, 1952 J. ROSAN 2,607,446

REPLACEABLE INSERT Original Filed June 25, 1949 3 WOW g/bsz'pr/ Roan/v Patented Aug. 19, 1952 REPLACEABLE INSERT Joseph Rosan, Balboa Island, 'Calif.

Continuation of application Serial No. 601,456, June 25, 1949. This application January 8,

1952, Serial No. 265,509

7 Claims.

My invention relates to replaceable inserts, the present application being a continuation of my prior application for Replaceable Insert, Serial No. 601,454, filed June 25, 1945, now abandoned, and a continuation in part, of my following copending applications:

Insert, Serial No. 466,855, filed November 25, 1942, now Patent No. 2,400,318 issued May 14,

Insert and Method of Replacing Same, Serial No. 490, 00, filed June 9, 1943, now Patent No. 2,407,904 issued September 17, 1946.

Among the objects of my invention are:

First, to provide a replaceable threaded insert which is adapted to be molded or cast in a body of material, and in the event of subsequent damage, may be replaced by a replacement insert of the type disclosed in the above identified copending application, SerialNo. 466,855, new Patent -No. 2,400,318 issued May 14, 1946.

Second, to provide a replaceable insert having a threaded shank, a flanged head and a locking means to prevent unscrewing of the thread, the entire insert being so constructed that it functions as a core to castin a body of material a threaded and counterbored socket capable of receiving, without further; alteration, my above mentioned replacement insert. More specifically, the flanged head of my replaceable insert may define a serrated counterbore adapted to .mate the serrations of a locking ring forming a part of my replacement insert, or a smooth counterbore of such diameter that the serrations of the replacement locking ring may broach into the walls of the counterbore.

Third, to provide a replaceable insert which does not require specialtools for its removal or preparation of the socket cast by the insert for reception of the replacement insert.

Fourth, to provide a replaceable insert which is particularly. economical of manufacture, easily molded in place, and which will not accidentally work loose.

With the above and other objects in view as may appear hereinafter, reference is directed to the accompanying drawings, in which:

Fig. 1 is a plan view of one form of my replaceable insert wherein a threaded counterbore and serrated socket is formed when the insert is cast in a body of material.

Fig. 2 is a longitudinal sectional view of my insert shown cast in a body of material, and indicating by broken lines the dimensions and depth to which the insert is drilled in order to effect its removal.

Fig. 3 is a partial sectional, partial elevational view of my insert molded in a body of material, showing the insert equipped with a stem or in- I tegral stud in place of the threaded socket shown in Fig. 2 and indicating by broken lines a tubular end mill for severing the insert to permit its removal.

Fig. 4 is a plan view of my replacement insert, hereinafter referred to as a two-piece insert, distinguished from my single-piece replaceable insert, this view illustrating the type of insert disclosed in my aforementioned copending applications.

Fig. 5 is a partial sectional, partial elevational view of my two-piece insert shown secured in the socket prepared by my single-piece insert.

Fig, 6 is a plan view of a modified form of my single-piece or replaceable insert, wherein the insert fiange is smooth.

Fig. 7 is a longitudinal sectional view of the insert in Fig. 6, showing the insert molded in a body of material and indicating by broken lines the drill employed to prepare the insert for removal.

Fig. 8 is a fragmentary longitudinal sectional view of the replacement insert shown in Figs. 4 and 5 as it appears secured in the socket prepared by the form of the single-piece insert shown in Figs. 6 and '7.

Fig. 9 is an elevational view of a further modified form of my single-piece replaceable insert, also indicating by broken lines the depth and position of a drill employed to prepare the insert for removal. v

Fig. 10 is another elevational view of a further modified form of my replaceable insert and illustrating a special pilot guided tool employed to effect its removal.

Reference is first directed to Figs. 1, 2 and 3. In this form of my single-piece replaceable insert the insert includes a shank I having a locking head or flange 2 at one end. As shown in Figs. 1 and 2, the shank l is tubular and provided with external threads 3 and internal threads 4. The external threads 3 are preferably coarser than the internal threads 4. The bore of the shank I may beclosed by a seal cap 5 in the formof a disc pressed into the end thereof.

The shank i need not be tubular, however, but

ing channel 9 is formed. Such channel also facilitates the external threading operation of the shank i when certain types of threading tools are employed; When other types of threading tools are employed the locking channel 9 need not be provided, in which case the external appearance of the shank is essentially that shown in Fig. 3. It should be'noted that the locking channel may be provided or omitted on either the solid or tubular shank.

The single-piece or replaceable insert is adapted to be molded in a body of material, for example, the insert may be formed of steel or other comparatively hard material and molded in a body of softer material such as aluminum, various die casting alloys, plastics, or the like. Such material, of course, must not be such that it welds to the surface of'the insert. It will'thus be seen that the insert functions as a core for casting in the body of material a threaded and counterbored socket, and that the counterbored socket is provided with axial serrations. The dimensions of such socket may be identical or approximately identical to the external dimensions of my two-piece or replacement insert .disclosed more fully in my copending applications. To facilitate and explain the use and function .of my single-piece insert, my two-piece insert is illustrated in Figs. 4 and .5.

The two-piece insert comprises a shank H which may be tubular and internally threaded or solid, and provided with a stud as in the case of the single-piece insert. The shank H is provided with external threads 12 corresponding to the external threads 3. The upper portion of the shank H is provided with longitudinally extending serrations I3 preferably within the annulus defined by the root and extreme diameters of the external threads l2.

'A locking ring l4 fits over the upper end of the shank H. The locking ring is provided with internal serrations which'mate with the serrations l3 and with external serrations I5 which fit in the serrated cavity or counterbore cast by the locking head 2 of the single piece or replaceable insert. The under side of the locking ring i4 is.

The single-piece insert whenmolded or cast within a body of material, is locked against removal by reasonof the serrations l, and in the case of the construction shown in Fig. 2; by the locking channel 9. Should the insert be damaged in a manner to require its removal, it is merely necessary to drill into the shank l to the depth indicated by broken lines A in Fig. 2 or B in Fig. 3, that is, into intersection with the uppermost of the external threads 3, and at a diameter approximating the outside diameter of said threads 3. When this is done, it is a simple matter to force a tool into the lower threaded end of the shank I and unscrew it. The annular extended portion of the locking head or flange can be readily removed by prying. It will be noted thatthe diameter of the drill required to separate the flange and shank for piecemeal removal, is smaller than the diameter of the flange. As a consequence, the drill does not overlap into the softer material in which the insert is molded, but is entirely guided by the socket within the insert, or the stud 6 as the case may be. As a consequence, a concentric hole may be easily drilled even when this operation must be performed in the field or under conditions in which hand tools or imperfect tools are available. This is important for the reason that in order to employ the two-piece insert shown in Figs. 4 and 5, it is highly desirable that the counterbore have the correct diameter and be concentric with respect to the threaded socket cast by the shank I. With ordinary care it is virtually impossible to damage the body of material in which the single-piece insert is cast in the course of removing the insert and replacing it with my two-piece insert.

In many cases, both the locking means afforded by the peripheral serrations 1 and the locking channel 9 are desirable. Thi is particularly true when the insert is used in relatively soft material.

In some cases either one of the locking means,

namel the serrations or looking channel may be omitted. Thus, in Fig. 3, the locking channel is omitted. In Figs. 6 and 7 a one-piece insert is are approximately the root diameter of the external serrations of my two-piece insert, or may have a diameter intermediate the root and peak diameters of these serrations. The thickness of the flange 23 is equal to or slightly greater than the thickness of the locking ring 14 of my two-piece insert. 7

My single piece insert shown in Figs. 6 and '7 is removed-in the same manner'as the first described structure, namely, by drilling as indicated by broken lines A into the shank until the lower end of the drill intersectsthe external threads 22. The drill, of'course, has approximately the same diameter as the extreme diameter of the threads 22. In so drilling, the material whichhas been cast into the locking channel 24 is destroyed so that, the remaining portion of the shank 2| may be unscrewed from its socket. The remaining annulus of the flange 23 may be readily pried from the counterbore which it has formed.

' The two-piece insert is substituted by screwing the shank H into the threaded bore cast by the shank Hand forcing the locking'ring Hl-v downwardly thereover. The external serrations l5 broach their way into the walls of the counterbore molded by the flange 23 so. that a firm looking connection'is provided. It will be noted that the socket which it is necessary to drill into the single-piece insert, may have a diameter suflicient to accommodate the pilot portion [6 of the twopiece insert. This minimizesthe required depth of the flange 23. By reason of the broaching action into the Walls of the counterbore formed by the flange 23, a very tight, firm connection between the locking ring and the body of the material is afforded, .and themed to turn. the shank of the two-piece insert until the serrations of the locking ring align with previously formed serrations, as is the case with the arrangement shown in Figs. 2 and 3, is avoided. It should be pointed out, however, that because of the relatively large number of serrations, such adjustment of the shank of the two-piece insert is not difiicult. V

In some instances, it is desirable to provide space for chips cut fromthe body of materialas the locking ring is forced in place. In such'cases it "is merely necessary to provide: a flange 23in the single-piece insert which has a' depth slightly in excess of the locking ring '14 of thetwo-piece insert, so as to form a clearance space designated If it is desired to have a locking channel deeper than the annulus between the root and extreme diameters of the external threads'3 or 12, or-to provide a larger shear area, a circumferentially ribbed construction such as shown'infFig. 9 may be employed. Here a, shank 3| is provided, having external threads 32 as in the other described structures. The upper portion of the shank is provided with an outer flange 33 corresponding to the flange 23 and an inner flange 34." Between the two flanges is formed a lockingjchannel 35. The root diameter of the locking channel maybe slightly less than the maximum diameter of the external threads 32 so that when a drill having the diameter of the external threads 32 as indicated by A in Fig. 9 is drilled into the insert, the shank between the flanges 33 and 34 is entirely removed. I i j The insert shown in Fig. 9 is replaced in the same manner as the previously described inserts. that is, the shank is drilled out until the external threads are intersected, the remaining portion of the shank is unscrewed, and the outer flange 33 pried from the counterbore which it has formed. In this case the inner flange 34 is left in place as it clears the parts of the two-piece replacement insert.

In some instances, it is possible to omit the outer flange 33 of the construction shown in Fig. 9, with the result shown in Fig. 10. In this case, the shank 4| is provided with external threads 42 at the upper extremity of which is a flange 43. forms a reduced portion 44. The advantage of this construction lies in the fact that the material molded into the reduced portion 44 may have a greater axial extent than is possible in the construction shown in Figs. 7 and 9, and consequently, offers greater resistance to any force tending to unscrew the insert.

This construction requires, however, that a special tool be employed to remove the insert, namely, a drill 5! having a pilot portion 52 adapted to fit rather closely in the bore of the shank, and a mill portion 53 suificiently large to form the counterbore for the locking ring M of my two-piece insert. This is made necessary for the fact that the material in which the insert is cast is almost invariably softer than the insert so that an ordinary drill, unless properly sharpened and adequately guided, would tend to cut Above the flange 43 the shank 4| or drill an oversize or eccentric hole that would destroy the counterbore in which it is desired to employ the locking ring of the two-piece insert.

It should be noted that the drill employed to effect removal of the single-piece insert, may be slightly smaller than the maximum diameter of the external threads. If this is done, the remaining portion of the shank I, 2| or 3| may be unscrewed even though the threads cut a slight mating thread in the material as the shank is unscrewed. The advantage in so doing, lies in the fact that the shank may thus be caused to engage the flange 2, 23 or 33 as the case may be, and force the flange from the body of material as the shank is unscrewed. The inner end of the shank, in each instance, is circumferentially substantially smooth so as not to interfere with the subsequent removal of the shank. For

a similar'reason, the undersidf-of'the head is sufficientlysmooth to" permitf its remo'val on severance from the 'shank. "1 11 In each of the constructions 'e'illustratedf including the Figs. 1, 2- and '3;-"tlie flange '2, y 23 or 33 as the case may be, is essentially circular in plan, so thatthe replacement' ring-may b'e accommodated irrespective of the "orientation of the insert. shown in Figs. 11, '2"'an'd 3 af'suffici'ent number of serrations are-provided so thatno appreciable turning movement of theshank of the; two piece insert is required to' accomplish registry between the replacement'rin'g and h serrations'in the walls of the counterboresl The several species of the nvention illustrated in Figs. 6, 7, 9 andl'O are disclosed and claimed in my copending applicationSeriaY-NQ 285,739, filed on'May 2, 19525 I In the variousfo'rms of sins shown, the internal threaded bare the shanks or the studs,"asthe case may-be, perform-the dual function of guiding the severing oo'l and affording means for-"thefattachment; o" reception of a tool employed=to "rerrlove theevere'd threaded portionof the shank;

Many other embodiments of the i'rw'ention-niay be resorted to 'without'departing froni the spirit of'the invention 9 1 I 1. In combination; a bed of material an insert, said insert-compr sing {substantially cylindrical shank havingextenor screw threads formed on at least a portion thereof and terminating in a circumferentially substantially smooth inner end; a rigid non-circular head portion having a circumferentially substantially smooth undersurface, said head portion being non-rotatably secured to the outer end of said shank and having a minimum diameter greater than that of said screw threads, said shank and head portion being molded in said body of material with the outer end of said non-circular head portion substantially flush with a surface ce inserts of said body and its outer periphery interlocked with said body; and means on said insert for receiving a fastening element for securing said body to an object, said insert being normally restrained against axial movement and rotation relative to said body by said screw threads and the non-circular head, respectively, and being capable of removal by drilling through said head and intersecting said threads to disconnect said head from said shank so that said head and shank can be separately removed from said body.

2. In combination, a body of material and an insert, said insert comprising: a substantially cylindrical shank having exterior screw threads formed on at least a portion thereof and terminating in a circumferentially substantially smooth inner end; a rigid head portion having a circumferentially substantially smooth undersurface, said head portion being non-rotatably secured to the outer end of said shank and having axially extending serrations on its outer periphery of a minimum diameter greater than that of said screw threads, said shank and head portion being molded in said body of material with the outer end of said head portion substantially flush with a surface of said body and its serrations interlocked with said body; and means on said insert for receiving a fastening element for securing said body to an object, said insert being normally restrained against axial movement and rotation relative to said body by said With rcgard to the construction screw threads ;the serrations, respectively, v

and being capable of removal by drilling through said head and intersecting said-threadsto-di-sconnect said headifroml said shank so -that said head and shan-k'can be separately removed from said body. r r

screw threads on the shank, said head portion having a circumferentially substantially smooth undersurface, said head portion being'non-r otatably secured to'the outer end ofrsaid shank and having :a "minimum diameter-greater than that of said screw threads; said shank and vhead portion being molded insaid body of material with the outer end .of :said nonvci-rcular head portion substantially'ifiush with a surface of said body and its outer periphery interlocked with said body, and means on said insert for receiving a fastening element for :securingsaid body to an object, said insert being normally restrained against axial movement and rotation relative to said body by said screw threads and the noncircularihead, respectively, and being capable of removal by drilling through said head and in- .8 tersecting said threads to disconnect said head from said shank so that said headand shank can be separately removed from said body.-

.4. A combination as set forth in claim 1,, in which the non-circular head portion is integral with the shank.

,5. A combination as set forth in claim 1, wherein: said means on said insert for securing a fastening element is an internally screwthreaded socket, said insert being closed at its axially inner end.

6. A combination as set forth in claim 1, wherein: said means on said insert for receiving a fastening element is an internally screwthreaded' .bore.

7. A combination as set forth in claim 1,

I wherein: said means on said insert for receiving .a fastening element .is an integral outwardly extending stud. V

JOSEPH ROSA-N REFERENCEsoIT-ED r The following references are of record in the file of this patent: v

UNITED STATES PATENT-S Date Germany Feb. 26, 1931 

